ludlow pattox perkins



A(No Model.)

L. P. PERKINS. STEAM OR-OTHER FLUID BOILER.

N0.l 529,304. Patented NOV. 13. 1894.

UNITED STATES 'PATENT OFFICE.

h LUDLOlV yPATTON PERKINS, OF MANCHESTER, ENGLAND.

sri-:AMOR oTHE'R FLuln BOILER.

SPECIFICATION forming part of Letters Patent No. 529,304, dated November 13, 1894. Application filed February 20, 1894. Serial lo. 500,919- (No model.) Patented in England July 24. 1893. No. 14,294.'

To all z vlwm t may concern:

certain new and useful Improvements in @Steam or other Fluid -Boilers; and I do hereby declare thefolllowing to be a full, clear, and exact description ofthe invention, which will enable others skilled in the art to which it appertains to make and use the'same.

Said invention was patented in Great Britain July 24, 1893, No. 14,294.

My invention relates to improvements in the construction of apparatus tor the gener-A ationof steam or pressure vapor and has for its object to increase the'ediciency of such apparatus and to remedy existing defects thereinmetically sealed tubes, each partiallyy filled with liquid, in combination with a vessel or chamber 'or a series of connected vessels or chambers containing the liquid to be evaporated.

The accompanying drawings y'illustrate the manner in which I propose to carry my invention into effect.

In the drawings: Figure l isalongitudinal section of a steam boiler. Fig. 2` is across section through the re grate of the same; and Fig. 3, an enlarged elevation, partly in section, of one of the tubes.

Referring to Figs. l and 2, a number of tubes a, a, each containing a quantityl of liquid and hermeticaliy sealed are vertically disposed -iu the furnace b and flue c. The upper ends of the tubes pass through the shell of the vessel d, and are made tight where so passing through, in the manner hereinafter describedand illustrated in Fig. 3.

, The vessel d, contains the liquid to be evaporated and the line e, e, indicates the normal liquid level. y The fuel is introduced through the tire door g, onto the tire-bars h, the necessary air for combustion being admitted through vthe door j. The door 7s, provides means for sweeping the outer surfaces of the tubes and for admitting cold air it it is desired t0 check the generation of steam. At l, is an ordinary bridge and at m, a door providing access to the flue c. The tubes immediately I employ amumberof separate her-- above the hottest part `of the tire'are shorter and consequently have less exposed surface than those on either side or in the due.

To enable the indicatedv forni of shell to withstand internal pressure .the tubes are made to act as stays and the portions of the tubes above the level of the liquid serve to dry the steam and to superheat it to some extent. i The ends ot the boiler may be stayed or strengthened in any ordinary manner.

The shell may be ot' any suitable'form other than the forin illustrated and the tubes may be disposed at any angle or angles whichwill allow the liquid contained to gravitate to the lower ends, or the tubesniay be bent in such a. manneras to act as iirebars, or to consti-V tute the sides or end of a fire-box.

The heated gases may be made to pass around the shell, or in any other direction but it is preferable that the hottest gases shall come into contact with the tubes before such gases come into contact with the ordinary heating surface ot' the boiler.

The quantity of liquid pnt into the tubes should besuch as that all the liquid contained in the tubes cannot be entirely converted into vapor which would lessen the efficiency of the tubes as conductors and permit vthe tubes to become overheated vowing to the fact that a comparatively slow circulation of superheated vapor would be set up instead of a series of rapid conversions, first of a liquid into'a va.-

por accompanied by alarge absorption of heat l from the tire, and then from a vapor vinto a liquid with an equivalent surrender of heat to the water contained in the boiler.

W hen it would be desired to generate steam ot' lsuch pressures as are generally now in use, say one hundred to one hundred and titty pounds per square inch and when the combustion of the fire wouldbe .under the condition of natural drafts, I should prefer that about one-fourth of the internal volume of the tube shall be filled with liquid, and that if one foot in length ot' the tube be immersed in the liquid in the boiler or' vessel, three feetshall be exposed to th-o action of the furnace or source of heat. I have found that it is not advisable in any case that the quautit of liquid within the tube shall be less than al out one-sixth or more than about three quarters of the capacityof the tube. l

The liquid which I prefer to use is witter but I do not confine myself to this liquid as it might; be advantageous to employ spirits, hydrocarbons or other liquids which here higher or lower boiling points or which better resist the eects ot' frost. I have found it advantageous in certein crises, pertieulnrly when tubes nre working et low pressures and temperatures, to exhaust them of nir ns for cends, giving out its sensible heat and in condensing, its latent heet, to the liquid in the boiler, the condensed liquid contained within the tu bes descending to be ngein evaporated. By suitably proportioni-ng the tubes, the in ternnl pressure may be so regulated as to nlwnys insure that the contained liquid shell be kept in contact with the interior of the lengthof the tube exposed to the furnace even with higher temperatures than nre genernlly employed. i

In Fig. 3 the method of fixing the tubes in place and of increasing the circulation is shown. The tube A is provided with e conej immediately beneath the plate a of the vessel d which forms e. tight joint therewith and is providedntits upperend with a nut k' which engages with the plate Z1 of the vessel, the lower edge of said nut being sharpened as shown, so as to mnke e. narrow metallic joint at l. A circulating tube m, provided with suitable apertures n, n, therein for the pessege of the liquid surrounds the tubes within the vessel and serves to materially increase the circulation ot unter around the tubes. Seid circulating pipes also act ns n distance piece between the plates ci and il of the vessel d. i

By constructing steningeneretors in accordance with rny invention, the following principal advantages dre obtained: I have found that these tubes evaporate more liquid than an equal amount of any ordinary heeting surface. ber ot' these tubes cannot empty the boiler, whether the i'nilure occurs within or without the shell7 und need not therefore necessitate the stoppage ot the boilers. L'ouids co- The failure of one or any num-` ter may be 'used in the generation of steam because any deposit of seele forming upon the tubes will be only upon their external surfaces and will, by increasing in thickness, allow their temperatures to rise and thereby to crack and detuoh the scale or sediment 4which will fall to the bottom of the water space whence it can be readily removed.

I would have it understood that I am aware that it has been proposed to use hermetically sealed tubes charged with minute quantities of liquidin the generation of steam, but on the application of heat to tubesso charged it has been found that they become red hot, thereby proving that. the superheated or suhns not constituted' a suiciently rapid me: dium for the transference of heat. aware that with a view of obvnting this fatal defect, apparatus known as Perkins high been used in connection with steam boilers, but in such apparatus wetter has been caused to circulate through closed tubes outwardly exposed to the water to be evaporated and to the heating furnace.

I do not therefore claim the use of the sealed in the manner substantially as hereinbefore set forth.

K1What I claim is- A steam generator, consisting of u vessel d, tubes u, partially tilted with liquid and hermetically sealed, said tunes extending diametricnlly across and engaging opposite walls of the vessel so es to strengthen the same, a, portion of said tubes being above the line of liquid therein, whereby the generated steam will be superhented n circulating tube m, extending entirely across and engaging with opposite wells of the vessel so as to strengthen the same, and having apertures n, surround'- ing the portion of each tube-a', within the vesselv (Z: and a, furnace b, for-heating the portions oijthe tubes a, outside of snidrvessel, substantinlly as set forth.

This specification signed and witnessed .the 2d dey of February, 1804.-.

y LUDLQW PATTON PERKINS. Witnesses: l

.T. ENTwisLn,

RICHARD IBBERSON.

taining large quantities of sedimentary met? pcrchnrged steam entirely filling such tubes` I am also' tubes excepting when charged and appliedl pressure hot water heating appnratusv hasl f 

